Auger bit



E. T. McPHERSON.

AUGER BIT.

APPLICATION FILED MN. i, 192].

' 1,417,760. Patented May 30,1922.

FATENT OFFICE.

ELMER r. MCPHEBSON, or WALLINGFORD, CONNECTICUT.

AUGEE BIT.

Specification of Letters Patent.

Patented May 30, 1922.

Application filed January 7, 1921. Serial No. 435,627.

To all whom it may concern.

Be it known that I, ELMER T. MCPHER- soN, a citizen of the United States, residing at /Vallingtord, in the county of New Haven and f itate of Connecticut, have invented. a new and useful Improvement in Auger Bits; and I do hereby declare the following, when taken in connection. with the accompanying drawings and the characters oi reference marked thereon, to be a full, clear, and er.- act description of the same, and which said drawings constitute part of this application, and represent, in

Fig. 1 a view in front elevation of my improved auger bit.

Fig. 2 a broken View thereof in rear elevation.

Fig. 3 a plan view thereof.

Fig. 4: a view corresponding to Fig. 2 but greatly enlarged.

Fig. 5 a view of the bit right angles to that of Fig. 4.

My invention relates to an improvement in auger hits, the object being to prolong the effective lite of bits of this character, notwithstanding hard usage; to prevent them from sidewise crowding in use and thus in sure the boring of true holes, and to simplify and cheapen the cost of manufacturing such auger bits.

With these ends in view, my invention consists in a balanced auger bit in which its cutting-edge and the smoothing edge of its spur are located substantially in line with each other.

My invention further consists in certain details of: construction as will be hereinafter described and pointed out in the claims.

In carrying out my invention, as herein shown, the cuttingedge 2 of the bit and the smoothing edge 3 of its spur i are located substantially in line in a plane lying close to the periphery of the base of its screw-point The said smoothing-edge 3 of the spur is axially extended away from the point 5, as at 7, considerably beyond or back from the cutting-edge 2 of the bit, at a right angle thereto, whereby the action of the bit is balanced in so far as the thrust of the cuttingedge 2 is oilset by the thrust of the smoothing-edge and vice-versa. This axial extension of the edge of the spur is produced by a groove in the head of the bit adjacent and parallel to the edge of the spur, one wall of which constitutes the cutting-face and its edge the cutting-edge of the said extension 4- a cutting-edge 2 of the spur. This balanced action of the cuttingand smoothing-edges prevents sidewlse crowding of the bit and makes the same work easily and smoothly, and results in the production of a clean hole. The prolongation of the smoothing-edge of the spur as at 7, as described, carries it far below the cu ting-edge 2 and far below the base of the screw-point 5, and also tar below the base line 8 of the heel 9 of the spur. Now, in case the spur is broken oil", or considerably worn away, the bit will still remain operative and eiiective on account of the length of its smoothing-edge 3, as described.

On the opposite side of the bit and at an angle to the plane of the line joining the with the smoothing-edge 3 of the spur 4, I form a relatively large flat face 10 in which the spiral channel 11 produced by the spiral rib 12 ot' the bit, terminates, though the spiral rib itself continues on until it ends in the cutting-edge 2. The flat face 10, which stands at an angle to the said line, forms a reinforcement for the spur, but its main advantage is in the manutao ture of the bit, since it enables the polishingwheel. to travel to the end of the channel and finish the same without further operations.

I claim:

1. A. balanced auger-bit having a spiral rib producing a spiral channel, the said rib terminating in the cutting-edge of the bit, and the channel terminating in a fiat face forming a reinforce tor the spur of the bit, and the said spur and cutting-edge being located substantially in line with each other.

2. A balanced auger bit having its cutting edge and the smoothing-edge of the spur located substantially in line. and the latter carried downward below the said cutting edge for balancing the action of the bit.

3. A balanced auger-bit having a spiral rib producing a spiral channel, the said rib terminating in the cutting-edge of the bit and the channel terminating in a flat face forming a reinforce for the spur, which is extended back from its root at a right angle to the cutting-edge of the bit, whereby the action of the bit is balanced.

in testimony whereof, I have signed this specification in. the presence of two subscribing witnesses.

ELHER T. MoPHERSON. lVitnesses MALCOLM P. NioHoLs, FREDERIC C. EARLE. 

